1. Field of the Invention
The present invention relates to a printing apparatus with an image reading capability, having a printing head and an image reading device, which are movable along an elongate platen to effect printing and image-reading operations on a recording medium on the platen.
2. Related Art Statement
One of the inventors named in the present application collaborated with another person to develop an image reading apparatus which is disclosed in U.S. patent application Ser. No. 726,314 which was filed Apr. 24, 1985 and was owned by the assignee of the present application at the time the present invention was made. Further, two inventors of the inventors named in the present application collaborated with two other persons to develop an another image reading apparatus which is disclosed in U.S. patent application Ser. No. 768,107 which was filed Aug. 21, 1985 and was owned by the assignee of the present application at the time the present invention was made. Such image readers comprise an elongate platen, an elongate guide member extending parallel to the elongate platen, a carriage movable on the guide member, and an image reading device which is mounted on the carriage and is adapted to read iamges recorded on a recording medium in the form of sheet of paper on the platen. In such image readers which have a relatively small image-reading portion, the images in a desired portion of the sheet of paper may be read by moving the image reading device relative to the recording medium.
The above-identified U.S. application Ser. No. 768,107 discloses, as a preferred form of a printing apparatus, a printer equipped with such an image reading device as indicated above, wherein the printing head and the image reading device are constructed as a unit mounted on a common carriage. In this arrangement, it is possible to use a common platen and a common drive device for the printing head and the image reading device. Thus, a printer with an image reading device is available in simple construction and at a relatively reduced cost.
In such a printer with an image reader in which the image reading device and the printing head are constructed as a unit, however, the image-reading portion of the image reading device is located close or adjacent to the recording medium even while the printing head is operating at its printing position adjacent to the recording medium. Consequently, the image-reading portion may interfere with an ink ribbon for the printing head, or may be subject to contamination due to exposure to fine particles removed from the ink ribbon or the recording medium. In the meantime, it is desired that the image-reading portion of the image reader and the printing head cover the same area on the recording medium. Simultaneously, it is a desire to reduce the size of the printer-image reader combination by minimizing the operating stroke of the carriage. To satisfy these two desires, it is preferred to construct the printer-reader apparatus such that the printing head and the image-reading portion are disposed as close as possible to each other. In this instance, however, the area of the recording medium in which the printing or image reading is being effected is broadly covered by the printing head and the image reading device, whereby it is difficult to visually check the currently printed or read area. The inventors of the present application recognized the foregoing inconveniences of the printer-reader apparatus indicated above.